Method and means for preventing leakage in valves



Oct. 13,1931. I w. LA MONT 1,

METHOD AND MEANS FOR PREVENTING LEAKAGE IN VALVES Filed April 2 192 l1Speets-Shet; l

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METHOD ANiJ MEANS FOR PREVENTING LEAKAGE IN VALVES W.-D. LA om 1,326,941

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METHOD AND "HANS FOR PREVENTING LEAKAGE TN VALVES 11 Sheets-Sheet 3Filed April 2, 92

I INVENTOR H4475? Dauauas AA/Va/v/T Oct. 13, 1931.

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METHOD AND MEANS FOR PREVENTING LEAKAGE IN NALVES Filed April 2, g 11Sheets-Sheet 4 5'2 48 INVENTOR ATTORNEYS Oct. 13, 1931. w. D. LA MONTMETHOD AND MEANS FOR PREVENTING LEAKAGE IN VALVES Filed April 2, 1926 llSheets-Sheet 5 INVENTOR Mzrrk 001/6445 [A /V0/v7 gTI'ORNEYS Oct. 13,1931'. w. D LA MONT 1,826,941

METHOD AND MEANS FOR PREVENTING LEAKAGE IN VALVES Filed April 2, 192 llSheets-Sheet 6 ATTORNEYS Oct. 13, 1931. w, D A T 1,826,941

METHOD AND MEANS FOR PREVENTING LEAKAGE IN VALVES Filed April 2, 1925 llSheets-Sheet 7 2 ee /a i 19 e4 93 'i F 84 i o 111:1 I 9 INVENTOR 144475/2 0006095 1/4/70;-

TTORNEYS Oct. 13, 1931. w. D. LA MONT 1,826,941

METHOD AND MEANS FOR PREVENTING LEAKAGE IN VALVES Filed April 2, 192 llSheets=$heet 8 INVENTOR MHz-R 00054145 4/1/70? WM M ATTORNEYS Oct. 13,1931'. w. D. LA MONT 1,325,941

METHOD AND MEANS FUR PREVENTING LEAKAGE IN VALVES Filed Apfil 2, 1925 llSheets-Sheet 9 INVENTOR .M; 75/? 00064/1-5 111%?- BY M 2 A ORNEYS 0a.13, 1931. D L M N A 1,826,941

METHOD AND MEANS FOR PREVENTING LEAKAGE IN VALVES Filed April 2, 1926'11 Sheets-Sheet 1o INVENTOR M4 727? flax/644$ 01/70/10 A ORNEXS Oct.13, 1931. w. D. LAMONT 1,826,941

METHOD ANDJEEANS FOR PREVENTING LEAKAGE IN VALVES Filed April 2, 1925 llSheets-Sheet 11.

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Gene/" a for Carbufiafor INVENTOR M1475? fiouams 1,4 Noxvr BY MMATTORNEYS.

Patented Oct. 13, 1931 UNITED STATES PATENT OFFICE.

WALTER DOUGLAS LA MONT, or NEW ROCHELLE, Nfiw YORK, ASSIGNOR 'ro LAmoivr oonronazrron, A CORPORATION or NEW YORK METHOD AND MEANS FORPREVENTING LEAKAGE IN VALVES Application filed April 2,

This invention relates to valves and its object broadly considered is toprevent fluid controlled by a valve from leaking therethrough or wheretwo fluids are separated by valve mechanism to prevent any mixture ofthese fluids. In some cases, one or both of these fluids may beair orone or the other may be various mixtures of gases. For example, in awaste heat steam generator system, to which my invention finds one ofits many practical applications, the waste gases from the gas generatorare led du'ringthe blow into a chamberwhere they may be used to heatwater for the production of steam. However, during the make, it 1snecessary that the combustible gases be completely shut ofi from thesteam generating chamber. It isalso necessary to prevent air fromleaking into said chamber, otherwise an explosive mixture might beformed; In

my corpending application; Serial No. 7 6,945, filed December '2, 1925,I have shown a specific application of my invention to this kind ofmechanism, and as described in said application, a valve closes theinlet from the gas generator to the steam generator chamber, and anothervalve closes said chamber from the atmosphere. Intothis chamber betweenthe two valves steam is introduced under such 39 pressure as willprevent anyleak past the lower valve, and likewise prevent the entranceof air through the upper valve.

The invention is, however, of a broader,

40. quite a small chamber may be employed with equally advantageousresults.

The invention, therefore, in one aspect may be viewed as a process'forpreventlng leakagebetween two pressure volumes separated by a valve,which consists in providing a controllable pressure volume in the pathof possible valve leakage. The valve structure itself may also be madeto contribute to the better sealing of the valve and in this aspect,

to the invention consists in a construction and 1926. Serial No. 99,243.

practical embodiment of means for practicing my improved process and isthere shown as applied to a clapper valve;

Fig. 2 is a sectional view of the embodi-.

ment shown in Fig. 1; I

Fig. 2a is a fragmentary sectional View showing a double chamberarrangement;

Figs. 3 and 4: are respectively a top plan and sectional view of anotherapplication of the invention to avalve structure; I

Figs. 5, 6,? and 8 are still other forms which the invention may take asapplied to a clapper valve installation;

Fig. 9 is a perspective detail of a modification;

Fig. 10 is a further modification of the invention as applied to aclapper valve;

Fig. 11 is an embodiment of the invention as applied to gate valves;

Fig. 12 shows an embodiment in which two check valves are used with achamber therebetween;

Fig.13 is a modification applied to large circular gate valves;

Fig. 14 is another modification applied to n u similar valves; scopethan is disclosed in sa d applicat on and 35 is susceptible of a greatvarlety of uses.

Fig. 15 shows a valve structure like that illustrated in Fig. 11, butwith automatic control;

Fig. 16 shows an application of the invention to a valve in which thefluid pressure tends to seat it in one direction;

Fig. 17 shows an application of the in-' vention to a valve tending tomove open by gravity and which is seated by the fluid pressure againstthis gravitational tendency;

Fig. 18 shows a rolling valve construction,

the view being taken in longitudinal section; Fig.19 is a section takenon line 19,-19,

Fig. 18; I

Fig. 20 is a section taken on line 20-.-20,

Fig. 18; n

Fig. 21 is a sectional view of a rolling valve, the valve designed toroll on a track;

Fig. 22 is a section on line 2222, Fig. 21;

Fig. 23 is a section on line 2323, Fig. 21;

Fig. 24 shows a construction similar to that shown in Fig. 21, exceptthat means are provided to give the valve a partial rotation at everyopening movement so that a different area is presentedto the seat;

Fig. 25 is a section on line 25-25 of Fig. 24; p

Fig. 26 is a section on line 2626 of Fig.

Fig. 27 shows a structure like that shown in Fig. 24 but arranged foroperation by a shorter piston stroke;

Fig. 28 is a horizontal section view of a rolling valve having but asingle seat;

Fig. 29 is a longitudinal sectional view of the same, showing the camarrangement for effecting firm seating and also an operating device;

Fig. 30 is a diagrammatic representation of curves taken by points atdifferent locations on the seating area; and

Fig. 31 shows the application of my invention to a steam generatorsystem.

The invention will be better understood by reference to the severalspecific embodiments now to be referred to. Referring to Figs. 1 and 2,1 represents a hinged valve, sometimes referred to as a clapper valve. Apintle 2 provides means of attachment for an arm 3, which is hinged at5, Fig. 1. This arm may be operated by power means so arranged that ittends to hold the valve tight- 1y. closed, or manual means only may beemployed. A circular groove 6 is formed in the underside of the valveand of less width than the width of the valve seat, such grooveconstituting a pressure chamber.

Now, let it be supposed Firstthat the valve 1 closes a gas chamber 7from the atmosphere and that when the valve is closed the pressure ofthe gas is greater than atmospheric pressure. If now the pressure in thechamber or groove 6 be maintained at atmospheric pressure, any leakagefrom chamber 7 into chamber 6 will be taken out of 6 through connectionslater to be described and none of the gas in cham her 7 will get intothe atmosphere. If. on the other hand, pressure in 6 equals that of thegas in 7', no leakage of gas will occur to chamber 6 and hence none tothe atmosphere. A somewhat higher pressure in 6 than in 7 would alsoprevent leakage from chamber 7 into chamber 6, although in this casethere would be a tendency to leakage from 6 into the atmosphere and alsointo chamber 7.

If the pressure in chamber 6 were less than atmospheric pressure, thenboth air from above the valve and gas from below 1t would ber 6. No gas,however, from 7 would get into the atmosphere, as any leakage past thevalve and into chamber 6 would be sucked out to be discharged at someremote place or otherwise disposed of. Likewise, any leakage from theatmosphere to chamber 6. This method may be desired when the gas in 7 isof a very poisonous kind, or very irritating to the membranes, aschlorine. In the case just described, the gases mix in chamber 6. Thismay not be always desirable and this chamber may be divided by a ring 6aas shown in Fig. 2a. With such double chamber, of course, theconnections by which the pressure will be controlled, would have to beduplicated.

Second-let it be assumed that the pressure in 7 is below atmospheric,and furthermore, that the mixture in 7 is such that it forms anexplosive mixture with air. When the valve is closed, and if the chamber6 is at that time also filled with air, then there would be a tendencyfor this air to leak from the chamber 6 along the path 12, into chamber7. This leakage would reduce the ressure in chamber 6, and air fromoutside t e valve would tend to leak in along the path a. If now asuction be created in the chamber 6 so that the pressure therein ismaintained just equal to the pressure in chamber 7, any air enteringchamber 6 would be drawn out of the same, and none would enter chamber7.

If the pressure in 6 equals that of the atmosphere, then while theremight be some leakage from chamber 6 to chamber 7, there would be noleakage of air into chamber 6, and hencenone to chamber 7. Of course, inthis case, the gas in 6 must be an inert gas or one which under thecircumstances may be introduced into chamber 7. If, however, thepressure in 6 were lower than that in 7, then any leakage would be from7 into 6 and also from the atmosphere into 6, but no leakage from theatmosphere to 7. Here again, a divided chamber 6 might be desirable.

From these examples, it will now be readily seen that the chamber 6provides a controllable pressure volume in the path of possible leakagebetween two pressure volumes separatedby a valve. It is also apparentthat the pressure differential in the chamber 6 may be varied to suitconditions.

If the pressure in said chamber is equal to the lower pressurecontrolled by the valve or equal to the higher pressure controlledthereby, there will be no leakage from one side of the valve to theother.

\If the pressure in 6 be higher than the higher pressure controlled bythe valve, there may be some leakage from 6 into both sides, but noleakage from the higher pressure side to the lower pressure side.

So also, if the pressure in 6 is below the as tendto leak through thevalve into the champressure on the lower pressure side of the valve,there will be no leakage between the sides of the valve, although theremay be leakage from both into the chamber 6.

If the pressure in chamber 6 is higher than 'the lower pressurecontrolled by the valve, but less than the higher pressure controlledthereby, there may, in such an event, be some leakage, although not asmuch as there would be without the chamber 6. It may sometimes besuflicient to prevent leakage to' a more or less extent but not highlyimportant to pre-' sure is higher than the higher limit, there is.

of course, a tendency to some leakage from i the chamber 6 towards bothsides of the valve.

Suitable pressure in the chamber or groove 6' to fit differentcondltions may be malntained in various ways and in the illustration,

flexible connections 8 and 9 are shown, these leading to "alvecontrolled pipes 10 and 11,

respectively. The flexible connection 8 at its other end is joined tothe conduit 12 which has three openings into the groove 6. The o herflexible connection 9 is likewise connected to a conduit 13 which alsocommunicates with the groove or chamber 6. Of course, conduits 12 and 13may be one continuous conduit. Valves 10 and 11 control suitable sourcesof pressure supply, whereby a partial vacuum may be maintained inthechamber 6, or various higher pressures, as desired. For 1nsta-nce,1fit is desired to maintain a pressure equal to the lower pressurecontrolled by the valve, then'a circulation of the fluid in the chamber6is preferably maintained if the fluid is gaseous, because under theseconditions there may be leakage from the higher pressure side of thevalve into the chamber 6, tending to raise the pressure therein if thispressure were not constantly lowered in like amount.

Circulation in the chamber 6 may also be desirable under the severalconditions above described, but a continuous circulation may not benecessary in all these cases.

If a pressure in chamber 6 is used which is less than the pressurecontrolled by thevalve, such pressure may be obtained and the valves 10and 11 closed. Of course, the pressure will gradually rise in chamber 6,if leakage thereto occurs from either or both sides of the valve, but atintervals the valves 10 and 11 may be opened, the pressure reduced andthe valves again closed. Various other methods of maintaining thedesired pressure in chamber 6 will be obvious. At times, it

connection.

may be desired to cool the valve and for this purpose, a cooling fluidmay be circulated in the groove 6. Such fluid, of course,

the chamber.6 and under such pressure that I it not only cools thevalve, but also prevents leakage.

If a relatively small quantity of water is introduced into the chamber6, and the valve is at a sufliciently high temperature, evaporationofthe water may be utilized to produce a vapor pressure, such as willprevent leakage of the fluid controlled by the valve. Qooling willlikewise take place under these circumstances.

Likewise, both water and steam may be introduced into the chamber 6 forboth cooling the valve and supplying the desired pressure underappropriate circumstances.

While in the embodiment shown in Fig. 1, the groove 6 is shown only inthe valve,it is obvious that a similar groove could be provided in thevalve seat. There is, however,

a practical advantage in having the groove in the valve only, because inapplying my invention to valves already installed, it is only necessaryto take ofl' the valve, and turn a groove in it. Whereas, to produce agroove in the seat would'be somewhat more dif- Under some conditions,however, it might be of advantage to provide a groove in the seat aloneor in both the valve and the seat.

In Figs. 3 and 4, this latter construction is shown. Here the valve 14is shown likewise as a clapper valve having a pi1'1tle15 and a pivotedarm 16 connected thereto by which the. valve is lifted, the arm beingsecured by a nut 17 There is a groove 18 in the valve and likewise agroove 19 in the valve seat. In

this case, the connections for maintaining fluid'pressure lead to thevalve seat groove and there need be no flexible connections emthere is agroove 21 in the valve seat and there is also a circular ring 22 formedon the valve and projecting below its edge and adapted to enter thegroove 21. In this case, likewise fluid pressure i maintained in thegroove 21 by a connection 23, and, of course, it is understood thatthere is also provided an outlet In Fig. 6, a valve 24 is shown with agroove therein. There is likewise a groove in the seat in which isfitted a circular ring having two openings, one connected to the inletconduit 25 and the other to the outlet conduit (not shown). The ring isof less tends all around the same. There is a small space 29 formed bythe trough 28 and the projection 27 and the trough 28 has a series ofholes 30 leading into this space. Openin s are made at suitable placesthrough the vave seat for the inlet and outlet pipes which connect thesource of fluid pressure or exhaust as the case may be, with the trough28.

In the form of device shown in Fig. 8, there is no groove formed ineither the valve or in the seat, but a recess is cut in the seat and.the

fluid pressure is introduced through a ring- 31 formed as shown with anopening around its inner edge. When fluid-under pressure is introducedthrough the pipe 32, there, of course, is produced a pressure betweenthe valve and valve seat in the path of possible leakage as in the otherforms already described.

Fig. 9 merely shows a slightly different form of ring from that shown at31 in Fig. 8 and in which perforations 33 are provided in an otherwiseclosed ring.

In Fig. 10, a spring ring 34 is secured to the valve seat and is adaptedto engage the valve 35 when the valve is closed. This ring is so shapedthat apressure chamber 36 is formed.

In Fig. 11, a somewhat diiierent kind 0-: valve is shown. In this formof the invention, there is a valve 37 or" the gate type and a valve 38of similar type and between them a pressure chamber 39. The fluid may beintroduced thereinthrough an inlet 40 and is circulated by means of anoutlet 41, both inlet and outlets being controlled by their own valves.Within the chamber 39, pressure of the desired amount may be maintained.Heretofore, the fluids considered have been treated as gases, but theinvention is not limited to fluids in gaseous form. Suppose the conduitto the right at valve 37 is filled with water. It now a pressure equalto the hydrostaticpressure in this conduit is maintained in the chamber39, no water can escape past the valve 37. 'Insuch a case, it would bepractical to use air as the pressure fluid in chamber 39.

A very similar condition is shown in Fig. 12 in which the valves 42 and43 are of the hinged variety and so placedthat they. will automaticallyclose on a reduction of pressure in the conduit. The principle of theinvention is, however, equally applicable to this type of valve.

In Fig. 13, the valve is of slightly differentconstruction and consistsof a circular portion 44 constituting the valve proper and a stem 45which is hollow. The casing for the valve is so made that the pressurechamber 46 is formed about the periphery of the valve. The fluid, may beintroduced through the valve stem and circulation maintained, ifdesired, by an outlet 47 leading from the chamber 46.

In Fig. 14, the conditions are substantially like those described inconnection with Fig. 13, except that there is provided a movable ring 48on one side of the valve, if such valve be a.v single valve, and asimilar ring 49 on the other side, if the valve be double. The valvecasing forms a pressure chamber 50 and the valve stem 51 is hollow. Whenpressure is introduced into the valve chamber, it causes pressure to beapplied to the inner face of each of the rings 48 and 49 and tends toseat these more securely, thereby preventing leakage by reason ofgreater pressure of the sealing rings against the valve seat as well asby introducing fluid pressure in the path of possible leakage. The rings48 and 49 are movable in their seats and there is a connection 52leading from the valve stem opening 53 into this opening behind therespective rings.

.The arrangement shown in Fig. 15 is quite similar to that shown in Fig.11, exce t that means are here shown for automatical y controlling fluidpressure introduced into the pressure chamber between the valves. Inthis figure, there is provided a valve 54, a valve 55, and a pressurechamber 56. The two valves are connected by a link 57 at the center ofwhich is pivoted another link 58. A lever 59 connects with the upper endof the link 58 and is pivoted at 60. The right hand end of lever 59 ispivotally connected to the piston rod 61 of a valve 62, which valvedetermines the "admission of fluid under pressure from a pipe 63 to thechamber 56. When the lever 59 is swung to open the valves 54 and 55, thevalve 62 is closed. When, however, the lever 59 occupies the positionshown in Fig. 15, valves 54and 55 are closed and valve 62 opened. Fluidunder pressure then passes along pipe 64 and by means of pipe 65 enterschamber 56. A pipe 66 is also connected to said chamber and leads to aspring controlled diaphragm valve 67 which automatically closes when thepressure in the chamber 56' chamber 7 3 is quite high, it wi l aid inclosing "plied to some of these.

of the valve. In this particular form escape of fluid from the chamber73 into chamber 74 is prevented by introducing fluid under pressure intoa circular chamber 75 formed in the valve seat and into which leads asuitable conduit 76 for supplying such pressure.

Fig. 17 is quite similar to Fig. 16, but differs from it in showing aconstruction in which the valve 77 is closed by pressure from beneathand in opposition to the force of gravity. A circular pressure chamber 78 is likewise provided which is supplied by fluid from conduit 79.

In quite a number of the applications of the invention to valves so fardescribed, a clapper valve of hingetype has been illustrated.

The invention, however, is equally applicable to valves of a rollingtype and in Figs. 18 to 29, I have illustrated my invention apalsopossess the additional advantage of keeping the seating faces clean.

In Figs. 18, 19 and 20, a rolling valve separates two chambers or.conduits 80 and 81. The valve shown is double faced, consisting of adisk 82 and a disk 83 supported by a shaft 84 and connected thereto bysplines 82a and 83a, respectively. A collar 85 is loosely mounted on theshaft between the two disks. These may be urged apart by fluid pressureintroduced between them as described in detail in connection with Figs.21 and 22. Formed with or connected to the disk 83 is a toothed disk 86.A track 87 in the valve housing 89 has a toothed portion 88 with whichthe teeth of 86 engage. The ,disk 82 bears upon the plane portion oftrack 87 'As the valve is moved from open to closed position, the disksroll upon the track, being compelled to do so by reason of the toothedmembers 86 and 87. This rolling motion causes grinding action betweenthe valve disks and the faces of the seat, tending to keep the surfacesclean, and resulting in a tighter seating valve. This grinding andsmoothing action will I be better understood by considering Fig. 18,

wherein curves have been drawn showing the path of a point m, a point 3and a point z. The circles c and d represent the inner and outerboundary of the bearing area ofthe valve face. The point w is just onthis outer circle. The point 2 is on the inner circle and the point isbetween the two but on the rolling circle. Other points on the valveface will describe similar curves and there will be crossings of curvesas the valve rolls into position in contact with its seat.

The curves described will, of course, de-

' pend upon the position of the rolling circle in respect of the circles0, and d. This is better illustrated in Fig. 30. Here, the roll- Therolling valves ing circle is represented at f, T being the track.

Any point as e on the radius will describe a curate cycloid, while anypoint such as 9' will describe the prolate cycloid. A point f willdescribe a cycloid.

Any other points such as 6 f and 9 will describe similar curves andthere will be many crossings of points on the valve face with points onthe valve seat. The result of this will be a smoothing ofthe faces ofvalve and seat and a better fit due to the rolling con tact. Theposition of the area of the valve which engages its seat may be thatdetermined by the circles e and f or by'the circles f and g. Or therolling'circle may be slightly within the outer valve contact circle asactually is the casein Fig. 18. Here the rolling circle passes throughthe point 3 the point a: being on the circle d and the point a on thecircle a.

In addition to this feature, I may also provide a groove 90 in the valveseat housing and connect this groove with an inlet 91 and outlet 92.Into this groove, fluid under pres- .sure may also be introduced andmaintained at such pressure as is necessary to suit differentconditions.

A groove may be provided on the other side and adjacent to the disk 82if desired. It isv obvious too that a valve having but a single disk maybe used.

A valve of the type just described may be quite large and. consequentlyheavy. I have therefore shown a conventional power means to operate it,such means taking the form of a cylinder 93 in which slides a piston94.- A piston rod 95 has pivoted to it a pitman 96 the latter connectedto the collar 85. A fluid. supply pipe 97 admits pressure to either sideof the piston under control of a valve 98 through conduits 99 and 100.

Figs. 21 to 23 illustrate another type of rolling valve, also shown asdouble faced. The valve housing 101 is provided with a track 102 andeach valve disk 108, 104 has a flange and a traction face engaging thetrack. A splined shaft 105 supports the disks for rotation together anda collar 106 loose on the shaft forms a hub for the pitman-107 connectedto the piston rod 108. A piston 109 slides in cylinder 110, the lattersupplied with valve controlled fluid pressure conduits as described inconnection with Figs. 18 to 20. In this form, the weight of the valve isrelied upon to furnish sufiicient traction to cause it to roll on itstrack when actuated by the operating means. A pressure chamber in theform of a groove 111 may be provided in the valve seat casing and theusual inlet and outlet conduits may likewise be-provided.

. valve is shown, as already described in connection with Figs. 18 to23. Thus, the two disks 112, 113, are connected by axle 114 and V thevalve of Figs. 24 to 26 is moved by power,

as described. v v

To provide for the rotary displacement mentioned, the valve disk 113 hasformed on it or connected with it, a ratchet'disk 115 engaged by a pawl116. The disks roll on their peripheries on a flat track, at the end ofwhich is a roller 117, Figs. 24 and 26, upon.

which the disks rest when the valve is in open position. The movement ofthe valve is sufficient to give it a partial rotation during valveoperation. Thus, a different part of the valve face is constantly beingpresented to the valve seat and compensation thus made for wear, warpageand like conditions, re-

sulting in a close and accurate seating of the valve.

The structure shown in Fig. 27 difl'ers slightly in the pawl and ratchetfeature and also in the power operating feature. Here,

- the ratchet 118 faces the other way and the .similar to that pawl 119may then give movement to the valve disks, just at the commencement ofthe closing movement.

The power means consists of a cylinder 120 already described, but thepiston 121 thereof is connected to the pitman 122 at a pointintermediate its fulcrum 123 and the point of application of the power,this form permitting a shorter piston movement. f

A single faced valve is shown in Fig. 28 and Fig. 29. This is also ofthe rolling type and consists of a disk 124 adapted to-roll on a track125 provided in the casing 126) Means to hold the valve firmly againstits seat take the form of a cam 127, one on each side of the valve andsupported by the casing. The' valve has across head 128, whose upperface is bevelled and is provided with a pin 129 at the central portionthereof, upon which the valve may turn as it rolls on its track to andfrom closed position. A cross bar 130 is supplied with side arms whichconnect with the cross hei fl-iand this furnishes a means of attachmentfor a rod 131 by which the valve is wet-operated. The rod has screwthreads 132 at its right end. These engage threads in a member 133secured to a worm gear 134, the latter engaging a worm 135 driven by asuitable motor 136. Rotation of the motor in one direction will actthrough the screw rod 131 to close the valve, while reverse rotationwill open it. The cam face of the cross head 128, by engagement with thecams 127 as the valve reaches closed position, will cause the valve toseat very firmly. A pressure groove may also be used in this formofconstruction, as in those forms previously described, such groove beingindicated at 137.

If the valve is sufliciently heavy, its traction may be sufiicient tocause it to rollon its track. However, a rack may be used to insure suchturning, if circumstances require it, and this may take the form shownin Fig. 18.

Likewise, pawl and ratchet mechanism as shown in Figs. 24 or 27 may beused.'

In Fig. 31, I have schematically shown how my improved valve sealingmethod may be practically used in connection with a system forutilization of the waste gases from a gas generator system.

Only enough, of the gas making unit is shown as will enable thisapplication of my invention to be understood. In the drawings, a watergas making plant is shown, the gas generating unit of which includes agenerator 137, a carburetor 138 and a superheater 139. The generator andcarburetor are connected near their upper ends by a conduit 140, whilethe carburetor and superheater are connected by conduit 141 near theirlower portions. At the upperend of the superheater, there is a conduit142 which leads to intermediate devices for washing the gases andfinally to the gas mains. During the socalled blow period of'i-he'rwater gas making process, the waste gases from the superheatermay be used for generating steam, and for this purpose, there isprovided a conduit 143 leading from the upper part of the superheater toa steam generating chamber 144. This chamber is provided with suitableheat absorbing units 145 and a baffle plate 146. The hot gases enter atthe top and are first deflected downwardly by said bafile plate and theythen pass upwardly and finally to the atmosphere through an outlet. 147.It has been already stated in the beginning of this specification thatit is important to prevent air from leaking into the steam generationchamber 144 during the"make period as well as to prevent the highlycombustible gases from pa ing from the superheaterinto the steam genrating chamberat this time. This may be accomplished most effectively bythe use of any one of several forms of myinvention already fully setforth.

For instance, in the conduit 143, I provide 1 two valves 148 and 149,which may be of the general form shownin Figs..11 and 15; The

stems of these valves are connected by a three armed member 150, to theupper arm of which is connected a bell crank 151, the latter piv- V otedon extension 152 on the steam generating chamber. The two valves aredesigned tobe opened and closed simultaneously and for this purpose anysuitable power device such particular form of valve structure becauseunder different circumstances, diiferent forms in which the inventionmay be embodied may be employed to suit particular circumstances.

In many cases, it may be desirable that the valves 148 and 149 andlikewise the valve 156 be opened and closed together and Ihaveillustrated a structure for doing this. Sometimes, however, it may bebetter practice to close the valves 148 and 149, either ahead of orafter the valve 156, or to close valve 148 before or after valve 149,and it is obvious that the construction could be readily changed to givea proper lag or lead to the closing movement of these valves.

I have shown the valve 156 connected to.

an arm 1'58 pivoted at 159 and connected to a bell crank lever 151 by alink 160 so that the same power mechanism 153 controls both valves. Itwill be noted from this description used very broadly and may include apressure greater than or less than the atmosphere so that sometimes thechamber may really actas a suction chamber as has been pointed outearller 1n the specification. When, however,

this chamber is to be used between the super heater and the steamgenerator, it is 'prefer-' able that the pressure in the chamber begreater than thepreslsure of the gases enteringi from the superheater.

he fluid used is preferably steam which may be obtained from anysuitable source and conducted to the chamber through a supply pipe 162-To effect economy of operation, I

, may provide for asufiicient supply of steam to not only maintain thedesired pressure in the chamber 161 to prevent any leakage through thevalves 148 and .149, but I may also conduct some or all of this to thewater gas generator 137 during the make period.

For this purpose, an outlet steam pipe 163 leads from the chamber 161andto the gener- 66 ator 137. During themake period, the

' ratin valves 148 and 149 are closed and steam is admitted through thesupply pipe 162 under control of a valve 164 which is then inopenposition. A second valve 165 in the connection 163 is likewise open sothat steam circulates through the chamber 161 and to the generator 137.The valves 164 and 165 may be controlled from the power device 153 andfor this purpose a lever 166 connects to the stem of the valve 165. Athree-armed member 167 has one of its arms connected to the stem of thevalve 164. Another arm of this member is'connected by a link 168 to thelever 166. The third arm is engaged by a lever 169, the upper end ofwhich engages a link 170 pivoted to the bell crank 151.

When the parts are in the position shown in the figure with the valves148, 149 and 156 closed, then steam passes to the generator 137 afterpassing through the pressure chamber 161, thereby preventing any valveleakage between the superheater and the steam generating chamber 144.The valve 156. prevents any air entering said chamber 144 and this valvemay be sealed by steam from the same supply as that which enters thechamber 161. For this purpose, a pipe .171 is provided. When the makeperiod has come to an end, the cylinder 153 is supplied with power atits left hand end to cause the piston to move to open the valves 148,149 and 156 and to close .the valves 164and 165. This is the so-calledblow period, and during such period, the hot gases flow into the steamgenerating chamber 144.

If, as already suggested, the valve mechanism in the conduit 143 is alsoutilized in the outlet 147 the steam may be conducted through bothvalves in series and to the generator 137, if desired.

Although I have illustrated a number of different types of structures,in which my invention may be embodied, there are still other forms itmay take, all within the principles disclosed. ,Some of the features ofthe several forms disclosed may be used without others, and manyvariations made, all within the scope ofthe invention without departingfrom the spirit thereof.

Having thus described my invention, what desire to secureby LettersPatent and claim is 1 The process-of preventing leakage between pressurevolumes controlled by valve mechanism which consists in causing a con- 1tlnuous stream of fluld in volume and under pressure to flow across thepath of possible valve leakage, wherebysaid volume of fluid acts as avehicle to carry any leakage and prevents the flow thereof from onepressure volume to the other. f 1 2. i In combination, valve mechanismsepatwo pressure volumes, a pressure;

cham r in the path of possible valve leakage between the pressurevolumes, and means for causin a continuous stream of fluid to flowthroug said chamber at suitable pressure and in such volume as toprevent the passage of leakage from one pressure volume into the otherthrough the valve mechanism.

3. The combination with avalve and a valve seat, of a support upon whichthe valve rolls in contact with the valve seat substan tially throughoutthe opening and closing movements thereof, a pressure chamber in I thepath of possible valve leakage between the pressure volumes controlledby the valve, and means for circulating a continuous stream of fluidthrough said chamber at suitable pressure to prevent leakage from onepressure volume to another through the valve mechanism. 1

4. An apparatus for preventing leakage between pressure volumescontrolled by valve mechanism in which said mechanism comprises twodiscs movable against their seats, and having a pressure chambertherebetween, and in which fluid from an independent source is caused toflow between the discs in a stream of considerable volume and under suchpressure 'asto cause them to be cooled by said flowing stream andpressed against their seats to prevent leakage between pressure volumes.

5. An apparatus according to claim 4, in which the valve rolls incontact with its valve seat throughout substantially the entire openingand closing movement thereof. 7

6. The process of preventing leakage between" pressure volumescontrolled by valve mechanism whiehconsists in causing a continuousstream of fluid in volumeto flow across the path of possible valveleakage, whereby said volume of fluid acts as a vehicle to carry anyleakage and prevents the flow thereof from one pressure volume totheother.

7. Process of preventing leakage between pressure volumes between whichthe normal flow is controlled by valve mechanism which consists ininterposing in the path of said flow of a fluidfrom-one pressure volumeto another comprising walls forming a chamber through which the fluidflows, means for closing ofi' the flow of the fluid through saidchamber, means for passing a second fluid in a stream of appreciablevolume through said chamber across the path of normal flow of the fluidbeing controlled, whereby the passage along said path of any of thefluid which leaks past the closing off means is prevented.

10. A valve mechanism for control of the flow of a fluid from onepressure volume to another comprising a valve body provided with seats,valves associated with'said seats and defining with the valve body achamber in the path of flow of the fluid, means for introducin a sealingfluid into the chamber, l

and means responsive tovariation in the pressure within the chamber forautomatically controlling said introduction so as to maintain in saidchambera suitable pressure to prevent leakage from one pressure volumeto the other.

Signed at New York, New York, this 30th day of March, 1926.

WALTER DOUGLAS LA MONT.

normal flow amobile pressure volume the movement of which serves toprevent the passage of leakage from the one pressure volume to theother. '8. A valve mechanism comprising a valve body provided withtwovalve seats forming openings throu h which flows the fluid to be Icontrolled by tie valve mechanism, a valve disc associated with eachvalve seat for closing its respective opening and definingf'with saidbod and seats a chamber in the path of flow of t e fluid means forcontinuously in-' troducing a sealing and cooling fluid into saidchamber and causing it to flow in volume therethrou h and to bedischarged from the chamber, w nerebly when the valve discs cover theopenings lea age through said openings of the fluid to be controlled isprevented.

9. mechanism for control of. the normal

